Senior Member of Technical Staff, Harness Engineering
About The Position
The company is addressing a significant problem in the commercial insurance industry where 36 million businesses in America need insurance, yet 77% are underinsured and 40% have no coverage at all. They are building an AI-led commercial insurance distribution system, experiencing rapid growth with approximately 1,000 new customers per month and 100x growth in the past year. The core of their operation is a shared substrate called the 'harness,' which supports every agent's loop, tools, execution environment, model routing, and multi-agent coordination. A brittle harness leads to brittle agents. This role focuses on building and improving this foundational harness so that pod engineers can develop and ship agents more efficiently, reducing development time from weeks to days. The thesis is that the model is only one component of a functional agent; the harness, encompassing the loop, tools, memory, execution environment, guardrails, fallback paths, and observability, is critical for an agent to perform useful work within a company. Harness engineers are needed to build this substrate, enabling other engineers to focus on shipping agents rather than rebuilding common scaffolding.
Requirements
- 3–6 years software engineering experience
- Production agent / LLM systems experience, including agent loops, tool integration, and prompt engineering at scale
- Strong written communication skills for API contracts, integration guides, and internal documentation
- Based in San Francisco or willing to relocate
Nice To Haves
- Sandbox/isolation infrastructure experience
- Open-source contributions to agent frameworks
- Foundation-model partner or early-access experience
Responsibilities
- Build agent loop primitives, including prompt construction, tool routing, retry/timeout/budget logic, and multi-step orchestration.
- Ship execution-environment infrastructure, covering sandbox lifecycle, isolation, blast-radius limits, and filesystem/network policy for agents.
- Own the tool layer for assigned domains, including schema, authentication, rate limiting, and observability for tools consumed by other engineers.
- Wire model-provider routing, including provider fallback chains, evaluation-driven model selection, and managing cost/latency tradeoffs.
- Ship improvements to the harness SDK to increase the speed and efficiency of pod engineers.
- Use the harness daily to write code, identifying and addressing rough edges.
Benefits
- Health, dental, and vision insurance
- Commuter benefits
- Team meals and snacks
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What This Job Offers
Job Type
Full-time
Career Level
Senior
Education Level
No Education Listed
